1. Field of the Invention
The present invention relates to an apparatus for carrying spherical objects without contact to the apparatus between the processes for manufacturing spherical semiconductor devices
2. Description of the Related Art
Conventionally, when a semiconductor device is made, a circuit pattern is formed on a silicon wafer, and it is diced in accordance with the necessity so as to form a semiconductor chip. Recently, in the above circumstances, there is proposed a technique in which a circuit pattern is formed on a spherical semiconductor (ball semiconductor) made of single crystal silicon, the diameter of which is not more than 1 mm.
For example, in order to make a discrete device, which is used for an MOS device, a solar battery or an optical sensor, of a spherical single crystal silicon, or in order to make a semiconductor integrated circuit of a spherical single crystal silicon, it is necessary to provide various processes such as a mirror polishing process, cleaning process, thin film forming process, resist coating process, photolithography process and etching process in which the spherical single crystal silicon is treated. In order to make the spherical semiconductor device effectively, it is necessary to connect the above treating and carrying processes with each other so that they can be formed into a line.
However, in the manufacturing processes, treatment is conducted not only in gas such as active gas or inert gas but also in liquid such as water or various solutions. In order to effectively manufacture and treat the spherical semiconductor devices, it is necessary to connect the manufacturing and treating processes with each other by pipe-shaped bodies such as pipes, and it is also necessary to carry the spherical silicon in the pipe-shaped bodies by a carrying force generated by fluid.
However, when the spherical objects are hydraulically carried as described above, the spherical silicon come into contact with an inner surface of the pipe. Therefore, a surface of the spherical silicon is worn out and further fine scratches are caused on the surface of the spherical silicon. Due to the foregoing, there is a possibility that the quality is deteriorated.
In order to solve the above problems, it is conceivable that the inner surface of a pipe, in which the spherical silicon pass through, is coated with a protective film so that the surface of the spherical silicon is not worn out. However, when the inner surface of the pipe is coated with the protective layer, the cost is raised and further it is difficult that the inner surface of the pipe is coated with the protective film of uniform thickness.
When surface treatment is conducted on a spherical single crystal silicon, or when a thin film is formed on the surface of a spherical single crystal silicon, or when photolithography is conducted, scratches caused on the surface could be a cause of pin holes in a thin film formed on the scratches, and further the pin holes could be a cause of leakage of an electrical current. Therefore, it is necessary to handle the spherical single crystal silicon very carefully.
When the spherical single crystal silicon comes into contact with the atmosphere, there is caused a problem of the formation of a natural oxide film or the pollution given to the spherical single crystal silicon. When the spherical semiconductor such as a spherical single crystal silicon is carried, it is preferable that the spherical semiconductor is carried in a closed space formed in a pipe-shaped body. Accordingly, when the spherical semiconductor is carried in the pipe-shaped body by a carrying force of fluid, it is necessary to provide a carrying apparatus in which the inner surface of the pipe-shaped body is not contacted with the spherical objects. However, such a apparatus has not been proposed up to this time.